IS STUPIDITY INBORN OR ACQUIRED?

Is stupidity in born or acquired? I personally feel that stupidity is in born. A stupid person will remain stupid, irrespective of the environment he or she gets. A stupid person doesn't know that he or she is stupid, you have to make him realize that you are acting foolishly. Accept for making a baffoon of themselves what do they get. I have not studied the genetics of a stupid person, but I am sure there must be set of some genes, that are responsible for stupidity. A lot more research is required in this area to establish the genetic origins of stupidity !